Variable propeller



Dec. 12, 1950 c. FUMAGALLI VARIABLE PROPELLER Filed Nov. l5, 1946 Ilinnlnz l @all 1111/1 llarlllll,

Patented Dec. 12, i950 UNITED STATES PATENT OFFICE This invention relates -to improvements in windmills for driving an electric generator or other power .supplying device, and `particularly to windwheel propeller constructions.

One Object of the invention is to provide windmill which is adapted to he manufactured and sold `at Ya comparatively `low cost, which is reliable .and ecient in action, which embodies a comparatively small number of parts ora `type not liable to `easily get Vout `of workingorder, and which requires Alittle attention and 1is Vautomatically controlled at Aall times to -prevent damage to the `working parts thereof or to thepower supplying device driven thereby.

Another object of the invention is to provide i'.

a windmill propeller which Vis operative to automatically Vary its effective diameter and Aworking speed and power under varying wind pressures and which iS-governed by controlling means operating'in conjunction :with the wind pressure i to regulate its speed so as to secure safe running of and prevent damage to the windmill and generator or other power supplying device driven thereby in the presence of -storinylv/ind speeds or gales.

A still further object of the invention is to provide a propeller which may be employed to drive a generator for charging a battery adjustable to vary its Speed together with associated control means controlled by and control-ling the vpropeller to adapt the propeller to operate at a :determined Yhigh speed regardless of wind pressures for rapidly charging the battery and until the battery reaches a predetermined high -rate of charge, and which control means may then be regulated or set to reduce the speed of `the propeller andthe charging rate to fully charge the battery without liability of injury thereto.

'Still another object of the invention is to provide .a windmill 'having an adjustable propeller of the character described, operating in conjunction with centrifugal means, .a mechanical controlling and transmission device, and the action of the wind, to vary its effective area or Cliameter to maintain a constant speed under diiferent wind pressures when a high gener-ating rate is required and to reduce its speed when a low generating rate is required.

.A still further Vobject of the invention is to provide novel means for shifting the propeller from high speed to slow .speed and .then governing it to Aoperate safely at 'low speed regardless .of wind speeds and pressures.

.A still further object `of the invention vis to i3 Claims. (Cl. H0- 74) provide a Vcon-struction which simplies Lwhile increasing `the `e'iiicienoy `of the windmill.

`With these land other objects in View, which will appear in the course or -thesubjoined description, the invention -consistsfof certain `novel features `of construction, `combination and arrangement of parts, Ihereinafter Vmore fully set forth and claimed, :and as shown in the accompanyingfdrawings, in which:

Fig. 1 is a vertical `longitudinal section through the windmillhead and upper portion of the tower of a windmill embodying my novel construction of propeller.

Fig. 2 is a transverse section taken on line `Zl-'Efof Figure l through the Adrive 4shaft and intermediate sleeve of the mechanicalcontroller, showing the sleeve housing and the yoke-lever in elevation.

Fig. 3 is a diagrammatic view exemplicatively showing positionsoi the propeller.

`Figure 4 :is a rsectional view taken on line '3-tl of Figure l looking toward `and showing particu- -lar-ly the construction of the brake device.

Referring now more particularly to the drawing, i y-designates the upper part `of `a windmill framefcr tower carrying an outer-stationary shaft .2 and `an inner shaft it rotatable therein, said shafts having iixed thereto turntable members `land between which are interposed `antifri'ction bearings t, and on which shaft 3 the windmill head 'l is mounted so as to be rotatably movablev to `maintain itself normally in the path of the wind. As shown, the upper .turntable member is preierably formed to providea housing enclosing collector'ringsfi and and associated brushes S and forrningp'artof `a current supply system including .Ya vbatteryito `be charged by fa generator when the windmill is used .to drive a generator, as hereinafter described. i

lThe windmill is oi .the tail vaneless `type and its head l .is in the form `of a streamlined body .or casing'in'cluding azpartly spherical or concavoconvex 4rotary rear end portion il forming the hub of the propeller, and front and `rear casing sections E2 `and it, the front .section .21 being in .practice closedat its forward end by a cowl or cap `piece (not shown), and the rear end of the casing being `closed by the member ll which has its :concaved side facing the casing section `it and `forming a chamber in open communication therewith. The section i2, which is separated from the section E3 by a stationary bearing head or partition it, forms an enclosure for the generator l5 or other power supplying device to be driven, and a brake dev-ice it, while rthe section i3 forms an enclosure for the rear portion of the generator drive shaft Il and the parts of a mechanical transmission and controller generally indicated at i3, governed by and governing the action of the adjustable propeller, whereby the speed of the propeller and charging rate of the generator are regulated.

The adjustable or variable windmill propeller comprises the hub il and a pair of diametrically disposed blades i9 projecting radially thereof and suitably contoured and having surfaces 2t facing forwardly for the action of the wind thereon to rotate the propeller even under the forces of very low wind pressures. The blades are fastened at `Itheir inner ends to the outer ends of bracket members El having staffs or arms 2i pivoted at 22 to the hub i l and provided with crank extensions 22 projecting into the hub toward the shaft and coupled by links 23 to a controlling sleeve 2d slidably mounted on the shaft il and which forms part of the control Vmechanism I8. The shaft il, as shown, extends rearwardly from the generator through and is journaled in the head Mi and extends outward at its rear end'through the hub. This end of the shaft il is splined to the hub li and threaded to receive a nut 25, by which it is fixed to rotate with the hub but is detachably connected therewith. Rotation of the propeller, therefore, effects rotation of the generator drive shaft il and armature in an obvious manner. The crank arms 22 and links 23 provide pivotal motion transmitting connections between the blades and sleeve 2d for sliding the sleeve inwardly or forwardly under the thrust of the blades when folding under increasing wind forces and for transmitting reverse motion from the sleeve to the blades to move the blades back toward their normal radial positions on relative reductions of the wind'forces.

Normally the blades I9 of the propeller project Youtward at right angles from the head i3 with their surfaces 2@ facing forwardly in the direction from which the wind is coming, as shown in Fig. 1 and in full lines in Figure 3, and the propeller blades act as tail vanes to rotate the head iii on the turntable d-- as the wind changes direction, to keep the head I3 in the path of the wind. From the position shown in Figure 1 and in full lines in Figure 3 the blades are movable rearwardly on their transverse pivots 22 to different rearward degrees or angles of inclination for feathering actions under varying and increasing wind forces to variable speed and power positions. As the blades move rearwardly to different degrees the diameter of the propeller progressively decreases as well as its effective area of surface exposed to the direct action of the wind and the angular position changes of the blades allows the wind to slip off the acting surfaces of the blades for a washout action, through which movements,

and against counter-centrifugal and pressure- Y resistances, provided as hereinafter described in accordance with the present invention, the propeller will be adjusted to secure its safe operation against high wind forces and to drive the generator at required and desired speeds regardless of wind forces. It is to be understood that the extent of backward movement or feathering action of the propeller lblades to different angles of incidence is such that within a given proportion of their full range of backward movement the adjustment of the blades adapts them to be driven for a fast current supplying and battery chargingY action at a substantially constant safe high speed regardless of the force of the wind,l

due to proportionate changes in angularity giving the same general speed at different Wind velocities, while during the remainder of their backward shifting range the diameter and area of the blades exposed to the wind will be reduced to the minimum intended to adapt the propeller and generator to be driven at a lower speed for a reduced current supplying and battery charging action. Y

The means for establishing an opposing centrifugal resistance to the backward motion of the propeller blades under centrifugal force engendered by the rotation of the blades comprises counterweights 25 attached to the inner ends of the blades or their brackets and `which are preferably of arcuately curved form to conform to the curvature of and straddle the casing i3 when the blades are in normal position. These counterweights may be of a size and weight proportioned to the size and weight of the blades to set up any desired or required resistance to the rearward movement of the blades and to cooperate with the mechanical pressure-resistance transmission and control device i8, so that the sensitiveness of the blades to changes in their angular position and that of the controlling means to the automatic adjustment of the propeller blades may be regulated to suit operating conditions.

The mechanical pressure-resistance controller and transmission i8 comprises the outer or rear sliding sleeve 2li, an inner or front sleeve 26 xed to the shaft Il and spaced from the head Vlli by a spacing and packing gland or sleeve 26', an intermediate sleeve 2l and bushing 21a slidable on and rotatable with the shaft il' and in a bearing housing 2l', a primary control spring 28v disposed betweenthe sleeves 2Q and 2l, a secondary control spring 29 disposed between the sleeves 26 and 2l, a control yoke-lever 3B having the upper ends of its arms 3U pivoted to a bracket 3! and formed in said arms with slots 3Go' receiving rollers Sill) on knuckle arms or spindles 33o projecting from housing 2l', whereby the lever is pivoted to the housing 2l', and a cable 32 attached to the joined lower ends of the arms of the lever and controlled by and controlling the movements of the sleeve 2l as hereinafter described.

The cable 32 from the lever 'etv leads downward over a guide pulley 5t to the upper rotatable part V5i of a coupling sleeve supporting withlthe non-rotatable lower half 52 of said sleeve a guide tube 53, the said sleeve parts and tube being suitably flanged to hold them assembled and-to permit of their up and down or floating movement and to permit independent rotation of sleeve part 5l with the head l.V A cable 32a forming a continuation of cable S2 extends downwardly therefrom and carries an elongated loop shaped connecting member 5s provided with aV roller 55 and having depending therefrom a cornpensating spring 56 from which is hung a weight 5l. The lower end portion and rollerr 55 of the member 5t are respectively adapted to receive and seat in the hooked end 53 of a suitablefholding device or latch member 59 whereby the lever 3s may be held in position to'set the controller i3 for a high speed propeller action.

The brake device It may be of ordinary type and as shown comprises'a drum 65 fixed to the shaft il', a pair of pivoted brake shoes 65 to engage the drum, a spring el to hold the'shoes normally retracted, links 68 connecting the free ends of thev brake shoes, and a rod 69 coupled'to VtheY holders 59, 59. in the workingoperation of the apparatus con.- l troller `lli when Areleased by disengagement of links foractuating the shoes. :Rod `y`.till lsgadapted yto be` operatedfby` a lever lllafrDm which depends :alcable `32a. carrying a connector dlsimilar gto connector 54 and -provided with a roller `55' ,to engage the hookenda' ofaholdingldevice 4or latch member similar to `latch member 5.9,;1Qm which connector 54' depends a compensating spring eeand `weight similar to the rspring e and weightggl attached tocormector.

Before .setting forth the controlling actions of the controller i8, itis believed to bedesirahle to describe :the working action of 'the propeller and the arrangement of the :parts whenathe apparatus is at rest, and the mannerin which .the apparatus :isthrown ,intoaction and the Controller rendered Operative :to govern theoperation of the; appara- -tus `and to throwit out of operation when the battery is lfully charged.

It is to be understood :that the apparatus is Ymanually Ithrown'into operation by engaging the connectors Ell, 5.55 with the 'holdersd 5 9 and is adapted to be thrown out of action by the disengagement of the connectors d, 15d from `the It is also to be understood ithat connector 54 from holder 5,9 allows the propeller to shift from high speed fast charging to Slow speed or slow charging position. Fig. l shows the apparatus as it appears, for example, after connectors 513, 5d are applied to holders, 59'- to re lease the brake andnold it released and to adjust the parts of thecontroller I8 to normal `positions and dispose theblades of the propeller in normal position to start the windmill -for high speed y,

' high to low generation rate as required, by the condition or state of charge of the battery.

When the propeller is in normal running position the blades and their counterbalancing weights balance each other and the sleeve 2;? lof controller I8 is in an intermediate position between the sleeves 2d and 26 with the springs 28 and 29 in a calibratedstate of compression and balancing each other and mutually opposing :backward movement of the propeller blades. Sleeve 2l is held in such position by the cable and latch 59 until it is released for action of weight 5l to move sleeve 2'! tothe left for a `mechanical controlling action allowing -an earlier and easier backward movement of the propeller blades for shifting them Awhile running from fast generating to slow generating position.

Assuming that the apparatus as shown in Figure 1 has just been set into action to operate the generator to charge a battery, for example, and that the battery at this time is in a low state of charge, it will be understood that the propeller blades will operate in normal position until the propeller is operating at high propeller speed and the generator is operating at high charging rate speed, and that thereafter the propeller blades will be governed as to position by the windpres- All sones :and the :action of the counterweshts f2.5.'

' andcontrollerl.

Initially -the propeller Adrives the generator at about 1% of its charging rate, the propeller idelivering enough power tordrive the generator, V but not suiiicient speedtooperatethe generatoriatfills maximum charging rate, the propeller `running like anat disk, fi. e., rwithits blades ;turningjina plane perpendicular tto thezplane of the head, fun- `tilitreachesafrptational speedoi, say BOOIBQPLM. lat a .windfspeed oi about 16 v to A1 8 M. P. H., `the generator delivering, for example, 4about 3,0 :amperes.

'lhe speed;and pressure of the wind force 'the propeller blades rearwardly to arfunnelwise fold ing posi-,tion'to a -certain degree of angularity of the blades. For example, as the wind `increases from, ;sayyl7 tcl8 M. P. to about 20 M. the propellerblades are forced to ,a vrearwardly inclinedzposition causing a reductionin mediameter of :the propeller decreasing its power rate, but which `proportionately increases its speed to about 1,0 00 R. P. of said propeller, or to a wind speed of 2 0 M. P. H., the loss ofthe-motoriizing power of the propeller being thus balanced to maintain the same famount of power Sunicient to Adrive the generator so that it develops its full charging rate at the moment the speed andgpower developed by the propeller enters into a balancing state.

In the event that the wind reaches'such aphigh speed as would be likely to cause the windmill -to overrun, causing damage to the windmill or to the generator, the furtherincreased pressure of the wind on the blades, supplemented by the centrifugal action of the c ounterweights, `will fold or force'the blades rearwardly toastill greater angle, changing the conoidal angle to such an obliqual degree that the wind partly slideslongitudinally 4and laterally and in deviousother directions off the obliquely surfaced blades, utilizing the Ditch of the rpropeller to apply compensating power suicient to maintain `proportional power and speed of the propeller required to keep it delivering the exact force necessary to drive the generator at sfull Charging rate. Any increased speed of the wind (pressure) causes the blades to `fold rearwardly to still greaterangles with an increasing loss in eiciency, and any 4decrease of the wind speed (pressure) will cause the blades to swing forwardly toward the flat running posi tion, increasing thepower eiiiciency of `the `propeller, in order to maintain a constant power and speed and to assure a safe running of the windmill at a speed of about, say, 20 M. P. H. ,of wind, even in the presence of the highest wind velocities driving the propeller, whose folding, feathering or reeling action lat wind speeds beyond such safe running wind speeds reduces the effective force of the wind on the propeller, so as to maintain a calibrated and constantspeedand power force to prevent damage to the windmill.

With this understanding the operation of the windmill is as follows, assuming the parts .to :be in the position shown in lig. l.

'In the operation of controller I8, sleeve .2l is `l'leld in the position shown in Fig. 2 through the connection including cables 32, 32a, :and connector 54 hung on holder 5 9, and `springs E6 .and 29 are held in a compressed and balanced state. Under the backward folding movements of blades I9 to different degrees sleeve 24 is forced inwardA to different degrees to slide sleeve 27 toward sleeve 25. These movements of the sleeve 27 may Compress .the sprnesnto a greater degree .but the 'springsfremain in a balanced state until on a nal range of inward movement Yof sleeveY 24 under the action of weight l sleeve 2l comes close to sleeve 26, relaxing spring 28 and placing spring 2Q under certain stronger compression. Parts 30', 3S, 32, 5l, 52 and 53 mayroat in the movements of sleeve 2'! but sleeve 2d will be held in its secured controlling position as long as connector 54 remains hung on holder 59. When, however, the connector 5t is released from the holder 59, the weight 5l is freed and moves sleeve 2l over its range toward sleeve 26, thus allowing spring 28 to expand whereby it is weakened, allowing the propeller to fold or shift from fast charging to slower charging position.

The propeller when governed in speed by the action of mechanism i8 remains at its normal running position, with its blades facing at right angles to the wind during low and medium winds until a certain slightly higher than medium wind prevails, using the complete power eiiiciency of said low and medium wind velocities, but when the wind reaches a certain higher than medium velocity and pressure and it tends to drive the propeller at a slightly higher speed, the propeller will initiate a governing action on account of the action of the excess pressure of the wind against the blades lil and the centrifugal action of counterweights This governing action of the propeller increases as the wind power increases, during which the blade angles change to maintain the propeller at the same governed R. P. M., regardless of high wind velocities. The propeller has two top governed speeds, first, one to maintain a high governed speed of the propeller when the wind reaches a certain speed as from 2G M. P. H. and up, and second, medium top governed speed R. P. lVi., as, for example, when the windreaches 14 M. P. H., the R. P. M. of the propeller being then controlled to medium top speed and commence governing at said R. P. M. to maintain such speed no matter to what extent the speed of the wind increases.

In this system as disclosed, the windmill has toV be set into rotating action by hanging the counterweight connector 5 on holder 59 which is also set by hand. The roller a5 of connector 54 may be set'at the same time on holder 59. The engagement ci connector 5d with holder 59 sets the speed controller mechanism i8 so that the springs 2s and 28 expand fully against the sleeve 2li. The propeller in this case will run freely at its maximum Speed until the generator reaches its maximum charging rate, and the propeller is mechanically governed to maintain this rateV until the wind reaches a speed that may be `harmful to the windmill parts and generator windings. As the windmill propeller is developing'its full power and speed and the generator driving a heavy charging rate through the battery, the charging rate must be controlled when the battery reaches a certain high state of charge in order tc prevent overheating and damage to said battery. lThe charging must be lowered to a certain point so as to continue the process of charge in a sare way until the battery reaches a fully charged state. As the battery stores the charge, the voltage increases in proportion. The charging rate may then be lowered by releasing the roller 55 of connector 54 from Vholder 59, the weight 5l, which drops, pulling cables 32a, 32, thereby operating lever Sii to slide sleeve 2 to the left, compressing the coil spring 29 and relaxing spring 2t so that it is weakened or its tension reduced to a certain point, depending onV the heaviness of the counterweightv 51, so that there is a calibrated but weakened pressure on the sleeve 24 against the folding action of the propeller blades i9 and the centrifugal action of the counterweights 25. The action of controlling the speed' of the propeller in the manner above described adapts the propeller to drive the generator so it generates a certain lowered but effective charge rate, and sets the apparatus so that it begins to control the speed and keep it constant when the propeller reaches a certainmedium speed controlled by the calibrated action of the weakened spring 28 depending on the amount of weight of the counterweight 5l.

Fig. 3 illustrates in full and broken lines the normal starting and initial running position at :c

and at y and c two of the many possible folding positions adapted to-be assumed by the propeller blades under different and progressively increasing wind forces. When the blades are disposed in position J: their acting surfaces are fully exposed to the force of the wind to drive the generator at comparatively high speed under moderate wind forces. As the blades fold to positions 'y and a, etc., under progressively increasing wind forces their working areas are reduced proportionately to the increases in wind speed. When the controller is set to balance the two springs the blades may fold under increasing wind pressures and unfold or move backwardly under relatively reduced wind pressures at any and all stages so that a certain substantially ccnstant rate of speed of the propeller may be maintained at all wind speeds within nearly the full range of folding movements of the blades. Flexibility in the folding of the blades under wind pressures and unfolding movements of the blades under the action of controller IS at relatively lower windspeeds is obtained, due to the construction Vof the propeller and controller, so that the windwheel will act easily, smoothly and with comparative silence at all speeds. When weight 5l is released from holder 59 and spring is allowed to have full and free expansion the blades may fold to still greater degrees, under high wind forces, to drive the shalt at sic-w speed, lrept substantially constant by the governing action of the governor it. Owing to the fact that the controller i8 acts uniformly on all the blades all the blades will be equally adjusted by the wind forces and the controller, preventing irregularities in the action of the blade and undue wear and tear on the mill and ensuring a smooth running action of the mill at all times.

From the foregoing description, taken in connection with the drawings, the construction, mode of operation and advantages oi my invention will be readily understood and Vappreciated by those versed in the yart without a further and extended description. t is to be understood, of course that while the constructions disclosed herein are preferred, changes in the form, construction and arrangement or the parts, within the scope of the appended claims, may be made, and equivalents employed, without departing from the spirit or sacrificing any of the advantages of the invention.

What'I claim is: Y

1. A winddriven propeller including in Vcombination a casingya shaft journaled therein, a hub xed to the shaft, a plurality of propeller blades pivotally mounted on the hub for folding movements conoidally fro-rnV a radial position toward andto different angular degreesJ with relation to the-shaftV under progressively increasing wind.

forces; amouter sleeveslidably mounted on the shaft,-pivotal motion transmitting connections betweenfthe outer` sleeveiand the'inner endsof the blades-1 adapting said sleeve to be moved in one direction from anormal position under thrust of the blades when folding under increasing wind forcesand adapting saidsleeve to be moved back to normal positionltotransmit unfolding movements to the blades as the wind forces are relatively reduced, ansinner. sleeve rfixed tothe shaft; anintermediatesleeve slidablymounted on the shaft, springs mounted respectively between the outer sleeve and the intermediate sleeve and between the intermediate'sleeve and the inner sleeve and actingA on `thetwo first-named sleevesto providey a yielding resistancev to the folding movementsof the blades, and means for adjusting. the intermediate sleeve to vary the resistance of one of.` thesprings relative to theother spring.

2.4 Awinddriven-proptller including in combinationa casing, a shaftjournaled therein, a hub Xed-to the shaft,.a,plurality. of. propeller blades pivotallyV mounted onv the hub for folding movements conoidally froma radial position toward and vto different-angular. degrees with relation to the sha-ftr under progressively. increasing wind forces, an outer sleeve. slidably, mounted on. the shaft,` pivotal motion transmitting. connections between the sleeve andthe linner endsvo-f. the blades` adapting the sleeve to bemoved in one direction froma normal positionunder thrust of theblades when folding under increasing wind forcesandadapting said sleeve to be moved back to normal position to transmit?` unfolding movementstc the bladesv as the wind'forces arerelatively reduced,.an `inner. sleeve fixed to the shaft', anintermediate. sleeve slidably mounted'V on the shaft, outer andi inner springs mountedv respectively` between the outer sleeve and the intermediate sleeve andbetween the intermediate sleeve and the inner sleeve and acting on the two firstnamedsleeves to provide a yielding resistance to the folding movements of. the blades, a device supported by and within the casing and operative to slidably adjust said intermediate sleeveto reduce. the resistance of the `outer. spring. relative to the inner spring, andmeans for securingsaid .device against movement toll-old the intermediate sleeve in suchladjustedposition and against slidingv movement. f

3. A winddr-ivenfpropeller includingin combination a-shafta.hub" red'tothe shaft, a plurality off propeller blades pivotally mounted on the hub for foldingmovements conoidally. from a radial position toward!- and todifferent angular degreesiwith relationitothe shaft` under progressively increasing windlforces, anouter sleeve slidably mounted on. the. shaft, pivotal. motion transmittingconnecticns between theouter sleeve andthe inner endsvof the blades: adapting the sleeve to be moved'in one directionfrom a normal position under thrust of the blades when foldingunder. increasing wind forcesand adaptingisaidsleeve to. be..moved...back .tonormal position to transmit. unfolding. movements to. the bladesas thewindforces are relatively reduced, airinner4 sleeverotatable with-the shaft, an intermediate sleeve.. slidable fon and rotatable with the shaft, compression andlexpansionsprings arranged respectively between the outer andintermediate sleeves andV between the intermediate andv inner sleeves to -provide a yielding. resistance tothe folding movements of the blades and to allow the `outerf anddntermediate sleeves to shift to-v` permit the-lblades toffold or causefthem to i unfold under wind forces of progressingly increasing and relatively reducedintensities, and meanslfor controlling the movements of the intermediate-sleeve to adapt the springs to-be balanced. or to.` adapt the outer spring to be weakenedwith respect to the inner spring.

4.. A` winddriven propeller including in combination ashafua hub fixed to the shaft, a plurality of propeller bladespivotally mounted on the hub1f for` folding movements conoidally from a radial position toward and to different angular degrees with relation to the shaft under progressivelyV increasing wind forces, an outer sleeve slidably mounted on the shaft, pivotal motion transmitting connections between the outer sleeve and theinner ends of the blades adapting the sleeve to be movedin one direction from a normal position under thrust of the blades when folding under increasing wind forces and adapting said sleeve to be moved baciato normal position to transmit unfolding movements tothe blades as the wind forces are relatively reduced, centrifugal counterv/eights connected to the inner ends of theblades` and extending at an angle to their axes toneutralize the centrifugal resistance of the-bladesto-folding movements, an inner sleeve rctatablewith the shaft, an intermediate sleeve slidable-on the shaft,.compression and expansion springs arranged. respectively between the outer andlintermediate sleeves and between the intermediate and inner sleeves to provide a yielding resistance tothe Vfolding movements of the blades and toA allow the outer andintermediate sleeves to -shiftto permit the blades to fold or cause them to unfold.` under. wind'forces of progressively increasing and relatively reduced intensities, and means forcontrollingthe movements of the intermediate sleeve to adapt the springs to be balanced or toadaptthe. outer spring to be weakened with respectY to the inner spring.

5l A. winddriven propeller including in combination a.shaft,.a hub fixed to the shaft, a plurality of propeller blades pivotally mounted on the hub fon folding movements conoidally from` a radial. position toward and to different angular degrees .with relation-to the shaft under progressively increasing wind forces, an outer sleeve slidably. mounted on the shaft, pivotal motion transmitting connections between the outer sleeve and the innerends ofthe blades adapting the sleeve to beimoved in one direction from a normal position under thrust of the blades when folding under increasing wind forces and adapting said sleeve to be movedb'ack to normal position to transmit unfoldingN movements to the blades as the wind forces are relatively. reduced, an inner sleeve rotatable with the shaft, an intermediate sleeve slidable. on the shaft, compression and expansion springs.arranged'respectively between the outer and intermediate sleeves and between the intermediate and inner sleeves to provide a yielding resistance to. thefolding movements of the blades and to allow the outer and intermediate sleeves to shift to permit the blades to fold or cause them to unfold under wind forces of 4progressively increasingandrelatively reduced intensities, and a deviceforsetting the intermediate sleeve in a position tending to keep the springs balanced andfto maintainlthe blades in radial position while permitting them `to fold under wind forces against a` predetermined-yielding resistance, said device being operable to adjust the intermediate sleeve to relatively bias the springs so as to reduce their resistance to the folding'of the blades under wind forces- 6. A winddriven propellerY including in combination a casing normally open at its rear end, a shaft extending longitudinally in the casing, a hub detachabiysecured to the shaft to rotate therewith and closing the rear end of the casing, a plurality of propeller blades pivotally mounted on the hub for folding movements conoidally from a radial position toward and to different angular degrees with relation to the shaft under progressively increasing wind forces, an outer sleeve slidably mounted on the shaft and normally abutting at its rear end against the hub, pivotal motion transmitting connections between the outer sleeve and the inner endg of the blades adapting the sleeve to be moved forwardly on the shaft from its normal position under thrust of the blades Y when folding under increasing wind forces `and adapting said sleeve to be moved back to normal position from such forward position to transmit unfolding movements to the blades as the wind forces are relatively reduced, an inner sleeve fixed to rotate with the shaft and mounted thereon forwardly of the outer sleeve, an intermediate sleeve slidably mounted on the shaft between the outer and inner sleeves, compression and expansion springs arranged respectively between therouter and intermediate sleeves and between theintermediate and inner sleeves to provide a yielding resistance to the folding movements of blades and to allow the outer and intermediate sleeves to shift to permit the blades to fold or cause` them to unfold under wind forces of progressingly increasing and relatively reduced intensitiesra support carried by the casing, a device pivoted to the support and coupled to the intermediate sleeve so as to be adjustable to control the movements of the intermediate sleeve to adapt the springs to be balanced in action or to bias the springs so as to weaken one spring with respect to the other spring, and means for holding said device in spring biasing position or releasing the same to restore the balancing action of the springs. Y

7, A ,winddriven propeller including in combination a horizontally disposed casing having a normally open rear end, a shaft extending longitudinally within the casing and projecting at its rear end outwardly beyond the rear end thereof, a concave-convex hub xed to the rear end of the shaft and closing the rear end of the casing with its concaved side facing said end of the casing, said concaved side of the hubhaving a central abutment surface, a controlling sleeve dising movement of the sleeve forwardly from its normal position when the blades fold under progressively increasing wind forces and operative to move the sleeve and blades backward toward their normal positions as the wind forces are relatively reduced.

8. A winddriven propeller including in combination a horizontally'disposed casing having a normally open rear end, a shaft extending longitudinally within the 'casing and projecting at its rear end outwardly beyond the rear end thereof, a concavo-convex hub fixed to the rear end of the shaft and closing the rear end of the casing with its concaved side facing the said end of the casing, said concaved side ofthe hub having a central abutment surface, a controlling sleeve disposed within the concavity of the hub and normally bearing at one end against said abutment surface, said sleeve being slidable on the shaft forwardly away from and backwardly toward said abutment surface, a plurality of propeller blades, bracket members fixed to the inner ends of the blades and pivotally connected to the hub and mounting the blades on the hub for folding movements ccnoidally from a normal radial position relative to the shaft toward and to different angula1 degrees relative to the shaft under progressively increasing wind forces, said bracket members having crank arms extending beyond their pivotal connections with the hubV toward the shaft into the concavity of the hub, links connectingthe crank arms with the sleeve to slide the sleeve forwardly on the shaft on the folding movements of the blades, an abutment in the casing and disposed about the shaft in spaced relation to and forwardly of the sleeve, a spring about the shaft between the controllingsleeve Y and abutment and providing a yielding resistance posed within the concavity of the hub and normally bearing at one end against said abutment f surface, said sleeve being slidable on the shaft forwardly away from and backwardly toward said abutment surface, a plurality of propeller blades, bracket members fixed to the inner ends of the blades and pivotally connected to the hub and mounting the blades on `the hub for folding movements conoidally from a normal radial position relative'to the shaft toward and to different angular degrees relative to the shaft under progressively increasing wind forces, said bracket members having crank arms extending beyond their pivotal connections with the hub toward the shaft into the concavity of the hub, links connecting the crank arms with the sleeve to slide the sleeve forwardly on the shaft on the folding movements of the blades, an abutment in the casing and disposed about the shaft in spaced relation to and forwardly of the sleeve, and a spring about the shaft between the sleeve and abutment and providing a yielding resistance to the slidto the sliding movement of the controllingsleeve forwardly from its normal position when the blades fold under progressively increasing wind forces and operative to move the sleeve and Yblades backward toward their` normal positions as the wind forces are relatively reduced, and centrifugal counterweights of arcuately curved form arranged Yat right angles to the blades normally about the casing concentric with the shaft and fixed to the inner ends of the blades and acting on the blades to neutralize the centrifugal resistance of the blades to folding movement.

9. A winddriven propeller including in combination a horizontally disposed casing having a normally open rear end, a shaft extending longitudinally within the casing and projecting at its rear end outwardly beyond the rear end thereof, a concavo-convex hub fixed to the rear end of the shaft and closing the rear end of the casing with Vits concaved side facing the said end of the casing, said concaved side of the casinghaving a central kabutment surface, a controlling sleeve disposed within the concavity of the hub and normally bearing at one end 'against said abutment surface, said sleeve being slidable on Y the shaft forwardly away from and backwardly toward said abutment surface, a plurality of Ypropeller blades, bracket members fixed to the inner ends of the blades and pivotally connected to the hub and mounting the blades on the hub for folding movements conoidally from anormal radial position relative to the shaft toward and to different angular degrees relative to the shaft under progressively increasing wind forces, said bracket members having crank arms extending beyond their pivotal connectionsV with the hub toward the shaft into the concavity of the hub,

assen-esa links connectingthe crank arms with the sleeve to` slidethe sleeve-forwardly on` the shaft on the folding movements of the blades; an. abutment sleeve in the casing. and slidably mounted on the shaft in spaced relation to andV forwardly of the controlling sleeve, a spring about the shaftV between` the controllingsleeve and"4 abutment sleeve providing a yielding resistance to the sliding movement of the controlling sleeve forwardly from its normalposition when the bladesv fold under progressively increasing* wind forcesand operative t'o-movesaid controllingsleeve-and the blades backward toward their normal positions as the wind forces are relatively reduced; and means for adjusting the abutment sleeve relative to the controlling sleeve to-vary the yielding resistance ofthe spring and for fixing said abutment sleeve in adjusted position. Y

10. A winddriven propeller including in combination a horizontally disposed casing having a` normally open rear end, a shaft extendinglongitudinally within the' casing, and'. projecting at its rear end outwardly beyondtherear endthereof, a concavo-convex hub fixed to the rear end of the shaft and closing the rear end of the casing with its concaved side facing the said end of the casing, said concaved side of the hub having a central abutment surface, a controlling sleeve disposed within the concavity of the hub and normally bearing at one end against said abutment surface, said sleeve being slidable on the shaft forwardly away from and backwardly toward said abutment surface, a plurality of propeller blades, bracket members fixed to the inner ends of the blades and pivotally connected to the hub and mounting the blades on the hub for folding movements conoidally from a normal radial position relative to the shaft toward and to different angular degrees relative to the shaft under progressively increasing wind forces, said bracket members having crank arms extending beyond their pivotal connections with the hub toward the shaft into the concavity of the hub, links connecting the crank arms with the sleeve to slide the sleeve forwardly on the shaft on the folding movements of the blades, an abutment sleeve slidably mounted on the shaft in spaced relation to and located forwardly of the controlling sleeve, an outer spring about the shaft between the controlling sleeve and abutment sleeve and providing a yielding resistance to the sliding movement of the sleeve forwardly from its normal position when the blades fold under progressively increasing wind forces and operative to move said controlling sleeve and blades backward toward their normal positions as the wind forces are relatively reduced, a support in the casing, an inner spring disposed between said support and the abutment sleeve and acting thereon in opposition to the first-named spring, a lever pivoted to the support and abutment sleeve whereby said sleeve may be adjusted to balance the springs or to weaken the outer spring with respect to the inner spring, and means for actuating the lever and holding the same and the abutment sleeve in adjusted positions.

ll. A winddriven propeller including in combination a rotatable shaft, a hub xed to the shaft, a blade adjusting sleeve rotatable with and slidable on the shaft, a plurality of propeller blades, bracket members fixed to the inner ends of the blades and having arms pivotally connected to the hub and mounting the blades thereon for folding movements conoidally from a radial position relative to the shaft toward and to different angular degrees relative to the shaft under progressively increasing wind forces, said armsofA the'bracketf members having extensions" rigid therewith and: projecting inwardly from the point'sof pivotal'connecti'onof thearms with the hub toward the-shaft, linksconnecting said extensions of the arms with the blade adjustingr sleeve to cause said sleeve to slide in one direction on the folding movements of the blades, anabutment sleeve slidably mounted on the shaft, aspring arranged betweenl the sleeves and actingA onsaidblade adjusting sleeve to provide a yielding resistanceto such sliding movement of the blade adjusting sleeve and folding movements of'theblades'under increasing wind forces and' for sliding the blade adjusting sleeve in the opposite direction to move the blades backwardtoward:I their normal radial position when the wind forces are rela-,tively reduced, a movablymounted controlling member connected to the abutment sleeve and operable for-adjusting said" abutment sleeve tovary the resistance of the spring to the sliding movement of the blade adjusting sleeve, and means for operating said member.

l2. A winddriven propeller including in combination a casing, a rotatable shaft arranged therein, a hub xed to the shaft, a controlling sleeve rotatable with and sli-fiable axially on the shaft, a plurality of propeller blades, bracket members xed to the inner ends of the blades and having arms pivotally connected to the hub and mounting the blades thereon for folding movements conoidally from a radial vposition relative to the shaft toward and to different angular degrees relative to the shaft under progressively increasing wind forces, said bracket arms having extensions rigid therewith and projecting inwardly from the points of pivotal connection of the arms with the hub toward the shaft, links connecting said extensions of the arms with the controlling sleeve to cause said sleeve to slide in one direction on the folding movements of the blades, a spring bearing at one end on said controlling sleeve to provide a `yielding resistance to such sliding movement of the sleeve and folding movements of the blades under increasing wind forces and operative to slide the controlling sleeve in the opposite direction when the wind forces are relatively reduced, an abutment sleeve adjustable on the shaft toward and from the controlling sleeve and bearing against the other end of the spring, a supporting member fixed to the casing, a yoke pivotally supported by said member and pivotally engaging the abutment sleeve, and means conto the yoke for operating the yoke to adjust the abutment sleeve to vary the resistance of the springs and for holding the yoke stationary to maintain the abutment sleeve in adjusted position.

13. A winddriven propeller including in combination a rotatable shaft, a hub fixed to the shaft, a blade adjusting sleeve rotatable with and slidable axially on the shaft, a plurality of propeller blades, bracket members fixed to the inner ends of the blades and having arms pivotally connected to the hub and mounting the blades thereon for folding movements co'noidally from a radial position relative to the shaft toward and to different angular degrees relative to the shaft under progressively increasing wind forces, said arms having extensions rigid therewith and projecting inwardly from the points of pivotal connection of the arms with the hub to- 15 ward the shaft, links connecting said extensions of the arms with the blade adjusting sleeve to cause said sleeve to slide in one direction on the folding movements of the blades, a spring bearing at one end on said blade adjusting sleeve to provide a yielding resistance to such sliding movement of the sleeve and folding movements of the blades under increasing wind forces and operative to slide the controlling sleeve in the opposite direction when the Wind forces are relatively reduced, a controlling sleeve adjustable on the shaft toward and from the blade adjusting sleeve and forming an abutment for the other end of the spring, a pivotally mounted operating member connected to the abutment sleeve for holding the abutment sleeve in a predetermined normal position and for adjusting it to vary the resistance Vof Vthe spring to the sliding movement of the blade adjusting sleeve in the first-named direction, and means for operating said member. Y

' CHARLES FUMAGALLI.

REFERENCES CITED Y The following references are of record in the ile ofV this patent:

UNITED STATES PATENTS' Number Name Date 191,168 Nesbitt May 22, 1877 212,236 Kuempel Feb. 11, 1879 607,774 Soellner July 19, 1898 i0 890,893 Eggleston June 16, 19,08 1,093,881 Payton Apr. 21, 1914 1,114,759 Heyroth Oct. 27, 1914 1,125,783 Waters Jan. 19, 1915 1,165,418 Kerr Dec. 28, 1915 15 1,178,729 Kemble Apr. 11, 19,16 1,362,753 Sperry Dec. 21, 1920 1,857,036 Wisk May 3, 1932 FOREIGN PATENTS 20 Number Country Date 342,777 Germany Oct. 24, 1921 647,287 Germany July 1, 1937 868,278 France Sept. 22, 1941 

